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This is a really big question, and @EnergyNumbers' answer addresses some of it. I'll try to address some more.
Battery End-of-Life
Your question is obviously referring to standard car batteries, which are used to power the car's starter motor. These are generally lead-acid batteries.
A true Electric Vehicle (EV) may have a small battery just like this ...
24
I think the first thing that comes to mind is what you can do to decrease the temperature around the home in the summer. I am here in Jakarta, Indonesia at the moment and I have found that covering the patios with container gardens has a remarkable impact. Beyond this, well-placed trees, and the like, can help a lot. If you compare the house where I am ...
24
I use PVGIS calculator to estimate photovoltaics energy gain to my satisfaction. It contains realistic Europe and Africa weather data.
Although this would be only a far estimate, let's assume you face south and you're based in Rome, Italy (instead of Chicago, IL), and we get:
a maximum of 1260 kWh a year with an optimal inclination of 34° and almost south ...
22
Mythbusters featured lightbulbs on Episode 69.
The conclusions they came to were
There is no appreciable lifespan impact from turning them off and on
There is no cost savings from leaving them on to "warm up"
Edit, FTFA:
Bulb Longevity
They tested one final element of this myth: frequently turning lights on and off decreases their life span, thus ...
22
You are broadly correct.
We can divide appliances into three broad categories:
Items that run off external low-voltage power supplies: Examples might include laptops (when connected to mains power), printers, etc. These devices depend upon external power supplies (nowadays usually switch-mode power supplies) to convert mains-voltage AC current to DC at the ...
20
EVs offer some definite advantages, and lots of advantages that depend on the specifics.
short answer: yes, it's better than driving a fossil-fuel car.
Long answer: it may seem to make less sense if you only consider a very small range of impacts, where all of the costs are visible, but only some of the benefits. Only when you zoom out to the long-term ...
19
Let's look at how much electricity and money can be saved by using solar thermal to heat a cylinder of hot water, rather than by using an electrical resistance heater.
Assuming a 100% efficient resistance heater (that's near enough to real values), and ignoring tank losses during the heating period.
180 litres of water is near enough 180kg.
The specific ...
19
Of course that depends on the battery, but Lithium Ion batteries were the standard for laptop/cellphone batteries last time I checked.
A battery feels most happy
being neither too full nor too empty,
being not too hot,
being not charged/recharged too often.
If you don't need the battery, remove it from the battery pack (at about 60%) and store it dry and ...
17
Although there is a definite allure to generating your own energy on-site, if you do not have good solar access then it is hard to get around that reality.
Instead, there are other ways to have renewable energy captured on your behalf:
If you have a choice of energy suppliers, buy 100% wind or solar generated energy.
Look into group solar. Perhaps you ...
16
Perhaps this article is what you are looking for? It's a study by the US Department of Energy on
the life-cycle environmental and resource costs in the manufacturing, transport, use, and disposal of light-emitting diode (LED) lighting products in relation to comparable traditional lighting technologies.
There is a similar study done by manufacturer ...
13
Do “100% renewable” electricity plans increase renewable electricity production? Well, it will depend on how the specific scheme is implemented, what the renewable suppliers are, and what timescale you are considering. So, the answer could be yes, no or maybe.
I don't know about your supplier's particular plan, and in order to keep this answer useful to as ...
13
Apparently a lot can be done. Fridge triage boxes look like a good idea:
Tracking what's inside the fridge with dry-erase decals also seem good, but probably takes a lot of time to manage properly. Keeping your fridge uncluttered is definitely good.
Grouping similar food types together in a refrigerator to increase the awareness of available foods has ...
13
TLDR; cadmium telluride panels have the highest EROI of the mentioned PV panels (around 34.2)
EROI estimates vary widely. This is because of differences in the method of calculation, scope of the study, installation location, assumed lifespan of a panel, etc. This also makes it relatively easy to manipulate EROI calculations.
Pessimistic
The most ...
12
I highly suggest buying a Kill-a-Watt type device which measure how much energy is used on an outlet. Test each appliance separately, and see which one is really sucking energy in your home and requires unplugging. It's the fastest and easiest solution to test precisely the devices you use.
(Note: This is a repeat of my comment, but I'm not getting any ...
11
i signed up just so i could make this comment. THelper♦ provided a good link to a DOE report on this topic, which i was researching because my roommate is skeptical about the advantages of efficient bulbs.
the report THelper♦ cited has the following bar graph that pretty much answers the question:
11
Someone has done it. A majority of the electricity I buy comes from geothermal energy †.
Of course, I live in the Pacific Northwest of North America, which puts me close to a tectonic plate boundary. This presents good conditions for extracting geothermal heat (since the earth's crust is thinner at such boundaries ... making shallower wells ...
11
I guess it depends on what you mean by "better".
The traditional way needs a pipe, the penstock, feeding as much clean water as possible from as high as possible directly onto a pelton turbine, which is connected to a generator.
The drawbacks are that the water must be as clean as possible and you should use all water for maximum efficiency. You also have ...
11
No. With nothing plugged in there is no circuit, so no current can flow.
An exception to this is if the socket or the switch has an indicator light - usually a neon one - that is illuminated when the switch is on. In that case the light will use a (very small) amount of power.
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Yes, we can. Estimates vary of the losses in long-distance HVDC (high-voltage direct current) transmission, but they're around 3-4% per 1000 km. Now, those operate at far higher voltages than you've mentioned: you wrote of 10 000 V, which is also written as 10 kV. HVDC runs at 100-800 kV, i.e. 10 to 80 times higher (100 000 to 800 000 V).
The idea of using ...
11
Consumer tests have shown that there are good and bad LED lights; indeed some of them do not reach their advertized life span.
I also have some bad experiences with LEDs dying long before their advertised end-of life, but that's anecdotes, not evidence.
You can imagine that actually testing these is hard, it takes a long time!
A major Dutch consumer ...
11
No. There is no readily available supply of net-positive-energy hydrogen on Earth, where most human power usage takes place. Hydrogen fuel cells may be a useful component of a total energy system but they are not a source of generation capacity. Hydrogen is more like a battery than a supply of energy. Hydrogen can be liberated from water by using energy. ...
10
So I’ve just put a system in place for this, it appears to be working okay. My plan was to reduce the amount of food that goes bad in the fridge, and, as a secondary goal, to eat a wider variety of foods and make sure that I washed up after myself and so on.
What makes this easy is that I have a favourite pan, I do pretty much all my cooking in my favourite ...
9
Here is what I do. I throw very little away if I am managing the food. This can keep waste down well below what people consider waste. It takes some trial and error to get right (no onion skins can't go in the stock bag and neither can squash skins), and those can be costly in terms of throwing stuff away but once you get it, this leads to hyper-...
9
If you compare a MC (monocrystalline) and PC (polycrystalline ) PV (photovoltaic) panel with the same full-sun efficiency in each case, there is very little difference in efficiency as light level falls, between the MC & PC panel.
For the same full-sun efficiency monocrystalline are slightly better in low light conditions but the difference is liable ...
9
The answer you are looking for would be contained in a Life Cycle Assessment (LCA). For an LCA you first want to determine the boundaries that are important to your question. Are you considering cradle to grave (disposal)? Cradle to cradle (recycling after use)? What are the boundaries for recycled source materials if used to make the light bulbs? The ...
9
I read somewhere that one issue (of several) that tends to shorten the lifetime of laptop batteries is heat from other components inside the laptop. So, if you happen to not be "on the move" with your laptop all the time, but instead end up using your laptop at the same desk for several days/weeks in a row, then you should remove the battery (don't forget to ...
9
DC motors: The most suitable motors are those which have permanent magnets in their rotors.
Traditionally these were pure DC motors - where DC was fed into the motor rather than AC such as is obtained from AC mains or via a transformer, but the boundary has become blurred as a BLDC motor or BLDCM = "Brushless DC Motor" uses electronics to take supplied DC ...
9
In the purist sense of "the electricity I use was actually generated by a wind farm", your idea is broadly correct. However, unless you actually have solar panels or a wind turbine on your house, that's not how the system actually works.
Broadly, all the electricity generators feed into the national grid (which in Australia covers only Qld-NSW-Vic-SA, but ...
9
No, you cannot get more energy out than you put in.
No, you cannot invent a perpetual motion machine.
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